Grading machine



H. F. MCDONELL April 30 GRADING MACHINE s Sheets-sheet 1 Filed July 19, 1944 Inventor fs'jaize 'WWW l Ail 30, 1946.

H. F. MCDONELL GRADING MACHINE Filed July 19, 1944 3 Sheets-Sheet 2 Inventor N\ 9N MMV um' RN mkv N Nm# n ll; MM. \N

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April 30, 1 946. H. F. MCDONELL GRADING MACHINE Filed July 19, 1944 5 Sheets-Sheet 3 I m/elztor Patented Apr. 30, 1946 assagso OFFICE GRADING MACHINE Hubert F. McDonell, Gainesville, F1a.

Application July 19, 1944, Serial No. 545,571

' 1 Claim.

The present invention relates to new and useful improvements in grading machines adapted for grading gravel and other coarse aggregates and the invention has for its primary object to provide a machine of this character adapted to accurately separate the material in a series of stacked screen trays having a screen mesh of various reduced sizes whereby to separate and collect the material in the respective trays.

An important object of the present invention is to provide a machine of this character embodying means for shaking the stacked trays as a unit in order that the liner material will gravitate downwardly through the successive trays.

A still further object is to provide a machine of this character of simple and practical construction, which is emcient and reliable in performance, relatively inexpensive to manufacture and operate and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming part hereof, wherein like -numerals refer to like parts throughout, and in which;

Figure 1 is a side elevational view.

Figure 2 is a longitudinal sectional view.

Figure 3 is a front elevational view.

Figure 4 is a fragmentary horizontal sectional view through the rear portion of the machine.

Figure 5 is a perspective view of one of the trays.

Figure 6 is a fragmentary perspective view of one corner of the inner frame.

Referring now to the drawings in detail wherein for the purpose of illustration I have disclosed a preferred embodiment of the invention, the numeral 5 designates an outer frame composed of angle iron members and including corner posts 6, upper longitudinal and transverse frame members 'I and 8, respectively, and lower longitudinal and transverse frame members 9 and I0, respectively, the latter being supported on a base structure Il.

An inner frame member as shown includes comer posts I3, upper longitudinal and transverse frame members I4 and I5, respectively, and lower longitudinal and transverse frame members, all of said frame members and corner posts being constructed of angle iron.

'Ihe opposite sides of the inner frame member are also provided with horizontal vertically spaced longitudinal tray supports I8 and the rear end of the inner tray is also formed with horizontal vertically spaced transverse tray supports I9, the longitudinal and transverse tray supports likewise being formed of angle iron and adapted to support a plurality of open trays 20 into stacked relation, each of the trays having a screen bottom 2|. The mesh of the vscreen bottom of the trays is of successively reduced size toward the bottom and the lowermost tray is formed with an imperforate bottom to constitute a pan.

The front of the inner frame is open and the front of each ofthe trays is provided with a handle 22 through which a' vertically extending retaining bar 23 is inserted, the retaining bar being received at its lower end in a socket 24`carried by the inner frame and the upper transverse frame member l5 of the inner frame is also formed with a socket 25 receiving the upper end of the retaining bar to lock the trays against movement in the inner frame.

Short lengths of cables 26 are attached to the inner frame adjacent the comers thereof and extend upwardly with their upper ends attached to the upper longitudinal frame members I of the outer frame whereby to suspend the inner frame in the outer frame.

pair of coil springs 21 are interposed between the front posts of the inner and outer-frames and a pair of rubber bumpers 28 are attached to the rear post 5 of the outer frame in the path of rearward movement of the inner frame.

A pair of bearing brackets 29 are secured to the post of the outer frame in which a transversely extending shaft 3U is journaled, one end of the shaft having a pulley 3| secured thereto driven by a belt 32 from an electric motor 33 supported on the rear end of the base II.

Secured to an intermediate portion of the shaft 30 is a cam 34 having a cam hump 35 formed on its peripheral edge, the hump terminating in an abrupt shoulder 36. The peripheral edge of the cam works against a roller 31 secured to one of the transverse tray supports I9 whereby it will b'e apparent that upon the rotation of the cam in the direction as shown by the arrow in Figure 2 of the drawings, the stacked group of trays will be moved forwardly to compress 'the springs 21 and upon being released by the cam shoulder 35 the trays will be moved rearwardly by the springs 2'I and strike the rear bumpers 28 to cause a shaking action of the trays. Accordingly, the material contained in the trays will be agitated and the liner material sifted through the screen bottom and thus graded according to size.

It is believed that the details of construction and manner of use of the device will be readily ible means suspending the inner frame in the l0 outer frame, a driven shaft journaled on the outer frame alongside the side of the inner frame opposite the open side thereof, a cam secured on the shaft and working against said opposite side of said inner frame to move the latter horizontally Y in one direction, and yeidabie bumpers between the frames and engaged by the inner frame during horizontal movement thereof.

HUBERT F. MCDONELL. 

